According to some, a comprehensive knowledge of TV Tropes (which I won't link to, saving you all time, money and time) is a reasonable substitute for a degree in English Lit, years of training in the field of psychoanalysis and, in extreme cases, a medical license.
Vocabulary! You never know what bizarre word a troper will use (especially if you're not native English) and you need to understand it! Then, whoa, you remember and start using it. Congratulations, your Vocabulary just got a +1 bonus!
TV Tropes is helpful for literature classes because you start thinking about literary works in the context of analysis, which is the entire point of most literature classes. (Well, that and the whole Everyone Is Jesus in Purgatory thing.) You just need to remember not to tell your college professor that the Ariadne myth hung a lampshade on the whole philandering-gods thing...
It even helps with Sociology! Show your professor a page like Eagleland Osmosis, and they make note of your research.
TV Tropes is also great for history if you have a teacher who likes film and books - for example, the History of Manga.
Try being a communications major and having notebooks FILLED with TV Tropes references.
One teaching method is to teach someone about particular concepts, and then present them with a story employing those concepts so that they can see them in action, or be challenged to find them themselves and explain the implications thereof.
TV Tropes also helps with Film Studies due to listing conventions.
Critical thinking! First, because carefully analyzing a work and breaking it down into its component tropes teaches you to carefully watch TV with a judging mind instead of just passively accepting the show. Second, because there's a reason you've became so acquainted with negative tropes, such as Author Tract or Wall Banger, as well as potentially negative tropes like Faux Symbolism: because they give you a solid base to justify why a show is bad!
Writing! TV Tropes can tell you all about a possibly negative trope in your work that you didn't even know existed. Now there are all sorts of stories which have been improved thanks to this wonderful website!
Homeschoolers? Learn this site. Love it. There's nothing better than free information when you're homeschooling.
Some learning disabilities (dyscalculia is one) work REALLY well with this site. You'll wonder how you tried to write without it.
Humour! If comedy is your style, the site's informal yet witty manner can help you become a generally smarter, funnier and more approachable person. What's more, entries about Acceptable Targets (along with the page Dude, Not Funny!) can help you avoid cracking jokes likely to offend people.
Useful Notes is, in a nutshell, Wikipedia if Wikipedia was a lot more practical and informal.
Friends! Out with someone and they suddenly make a reference to Parental Bonus? Instant BFF!
Bored of your favorite shows, movies or book series? You will be able to enjoy your favorite things once more because all the Wild Mass Guessing combined with finding new content and the overall descriptions the tropes provide. Not only you can find new content to try out, but you have a new way of seeing your old shows and books as if you are reading them for the first time.
Although TV Tropes has its downs, it's still a really great place (sorta like real life). It helps you learn about awesome media and cool tropes to use! It's funny, it's heartwarming, it's awesome, and it's everything you wanted!
What if a storyline component suddenly reminds you of a trope you know next to nothing about? Seriously, who knew you could catch a Genghis Gambit as soon as you learned about the event? Congrats, you've just been enriched!